The present invention relates to an arrangement for sealingly closing an opening in general, and more particularly to an arrangement of this type which is suitable for use in connection with an inlet and/or outlet opening of a vessel having an internal space in which a chemical reaction or chemical reactions take place. Still more particularly, the closing arrangement according to the invention is suited for use at the charging and/or discharging opening of a coking oven.
There are already known closing arrangements of this kind which include a frame member on the vessel which bounds the opening and a closing member or door which is movable between a closing position in which it bounds a gap with the frame member and an opening position in which the closing member exposes the opening, wherein the closing member overlaps the frame member so that the aforementioned gap extends outwardly from the opening and wherein the sealing arrangement includes two sealing elements or blades which extend all around the opening with outward spacings from the latter as well as from one another in the closing position of the closing member, the sealing elements being mounted on one of the members and extending therefrom across the gap and into contact with the other member to define between themselves an enclosed sealing space which is filled with a gaseous medium.
Vessels equipped with this type of sealing and closing arrangement are customarily used in preference to vessels equipped with other types of sealing arrangements when the chemical reaction or reactions taking place in the internal space of the vessel require performance at, or result in the development of, high temperatures, and when the gases developing or liberated during the performance of such reaction or reactions can no longer be retained in the internal space of the vessel with a sufficient degree of reliability by resorting to the use of a simple sealing arrangement, so that such gases could escape past the simple sealing arrangement through the gap between the frame member and the closing member and constitute a burden to the environment or a hazard or nuisance to the operating personnel.
An environment in which the sealing arrangement of this type can be used in a particularly advantageous manner is that of a coking oven, particularly a coking oven the frame member and the closing member of which extend along a substantially vertical plane in the closing position of the closing member or door.
While it is true that, in the heretofore known embodiments of the sealing arrangements of the above-discussed type, it was possible to achieve the gap-tightness of the closing arrangement in the closing position with a high degree of reliability by resorting to the use of the aforementioned doubled sealing elements defining the sealing space therebetween, there was still present an important drawback, namely, that the materials usually selected for the sealing elements had a relatively short life span under the conditions of use thereof, that is, when exposed to the relatively high temperatures prevailing in the internal space of the vessel or at the vicinity of the opening. Also, the sealing action of the sealing arrangement was less then complete under many circumstances, especially when the sealing elements were constructed as relatively rigid sealing blades or similar elements, inasmuch as either the frame member or the closing member or both are likely to suffer deformations under the influence of the high temperatures, which varies the size or width of the gap, possibly to an extent where the sealing elements would not be able to compensate for such variations, and inasmuch as deposits or encrustations are likely to develop on the frame member or on the closing member around the opening, especially when the sealing arrangement is being used in a coking oven, where they would interfere with the ability of the sealing elements to contact the opposite member to that on which such sealing elements are mounted and hence let the potentially noxious or hazardous gases escape past the sealing elements through the interstices between the encrustations, the sealing elements, and the opposite member.